The present invention relates to disposable absorbent articles. More particularly, the invention pertains to elasticized absorbent pads that are adapted to assume and maintain an effective bucket shape during use.
Absorbent pads for menstruation or urinary incontinence are intended to absorb and retain body fluids. Such pads typically comprise an absorbent structure disposed between a fluid (or liquid) permeable topsheet and a fluid (or liquid) impermeable backsheet. Leakage to the side has been a problem when using absorbent pads. This has been a problem in all types of absorbent pads, both the older types, i.e. thick and wide pads, and in more modern types, e.g. so-called body-shaped pads, which vary in thickness along their lengths and are relatively narrow in the mid-section where the pads are thickest.
The older uniformly thick pads are often greatly deformed during use quite simply because the pads are too large and not fitted to the shape of the human body. Such pads are not resilient and deform with the movement of the wearer's body. The pads usually press together in the mid-section and bend along a longitudinal axis such that the garment-facing side folds back onto itself and the body-facing surface becomes convex with portions of the topsheet layer facing out toward the sides of the pads, resulting in a reduction in effective fluid-retention. Leakage results from the folding and shifting movement of the pad.
Attempts to solve these problems have resulted in pads having shapes that follow the shape of the body and having the greatest absorption capacity where the need is greatest. These modern pads do not deform especially much during use and are typically more comfortable. However, side leakage is still a substantial problem even in the body-shaped pads. On occasions when fluid discharge is great, not all the fluid is absorbed rapidly enough, rather, a portion of the fluid can leak out to the sides of the pad.
More recent developments have resulted in thinner pads. This has been made possible both by compressing the absorbent material, and by using high-absorbent materials. However, side leakage is still a problem as such pads do not conform to the body. Since the pads are usually very thin, the pads must be relatively broad even in the middle, making the pads liable to be greatly deformed during use, unfortunately often resulting in side leakage.
Many pads leak when an insult of fluid escapes off the side edges of the pad before the fluid can be absorbed. This leakage is more likely to occur after multiple insults when the absorbent assembly or core is more saturated. Many pads have the ability to maintain contact between the pad and the wearer's body when the pad is dry. Unfortunately, after at least one insult of fluid, the body-facing surface of the absorbent assembly or core shifts, swelling upward or drawing downward to the point of disrupting contact between the pad and the wearer's body. This disruption reduces the effective gasketing along the side edges of the pad.
Many different attempts have been made to eliminate the occurrence of side leakage. In thin pads, one example is to arrange a number of longitudinal compressed areas in the absorbent assembly or core for the purpose of rapidly spreading the fluid longitudinally. These compressed areas are, however, far from sufficient to satisfactorily eliminate side leakage.
It is also known to further widen the fluid-impermeable backsheet layer so as to cover, in addition to the back and side edges of the pad, also a portion of the body-facing surface. In such a design, the fluid already collected in the absorbent assembly or core is effectively enclosed. However, there is the substantial disadvantage in that the fluid-impermeable backsheet layer is folded in over a portion of the body-facing surface, covering a major portion of the body-facing surface of the pad. When the pad is deformed during use, fluid can run directly out of the pad over the portions of the backsheet layer folded over the body-facing surface.
Absorbent pads have also incorporated elastic members in an attempt to form a bowed shaped or a bucket-shaped product with the goal of better fluid containment and improved leakage performance. Present elasticized pads have been less than successful in achieving this goal. One reason is that the elasticized sides of many existing pads create ineffective barriers to fluid movement. In some current absorbent pads, for example, the elastic structures tend mainly to bunch the pad, and particularly tend to bunch the absorbent assembly or core in the central portion of the pad. As a consequence of ineffective elastic utilization, current absorbent pads are subject, much too commonly, to failure in the form of leakage.
Thus, there is a need for an absorbent pad with elasticized side flaps that provides a bucket-shaped receptacle with effective elastic members. In addition, there is a need for an absorbent pad with effective gasketing characteristics creating a barrier that reduces side leakage not only when the pad is dry but also after multiple insults and heavier fluid loads.